Answer:
c. If Jack does not accept the $100,000, there is a valid contract for the sale of the business, without a non-competition clause.
Step-by-step explanation:
If Jack, Sophia, and Hal enter into a contract to close on the business without the non-competition agreement, and Jack stated that he would probably sign the non-competition agreement if they included an extra $100,000.
If a month later, Hal and Sophia bring Jack $100,000. the result will be If Jack does not accept the $100,000, there is a valid contract for the sale of the business, without a non-competition clause.
Jack CAN change his mind, since he stated that he would probably accept $100,000 additional for the non-competition agreement.